The present invention relates to a magnetic write element for use with disc drive storage systems. More particularly, the present invention relates to a magnetic write element having a narrow top pole and a method of forming the same.
Thin film magnetic read/write heads, such as magnetoresistive (MR) and giant magnetoresistive (GMR) read/write heads are commonly used in disc drive storage systems. These read/write heads typically include separate read and write elements for reading data from and writing data to a magnetic disc. One advantage to this configuration is that the read and write elements can be optimized for the particular task they are to perform.
The write element of the read/write head generally includes a conductor coil, a bottom pole, and a top pole separated from the bottom pole by a writer gap. In operation, an air bearing surface (ABS) side of the top pole, bottom pole, and writer gap face, and are in close proximity to the rotating magnetic disc. During a write operation, an electrical current is caused to flow in the conductor coil, which induces a magnetic field in the top and bottom poles, that extends across the writer gap therebetween and into the rotating disc. This causes magnetic moments, which represent bits of data, to be impressed upon the disc in concentric circular tracks.
There is a never ending demand for higher data storage capacity in disc drives. One measure of the data storage capacity is the areal density of the bits at which the disc drive is capable of reading and writing. The areal density is generally defined as the number of bits per unit length along a track (linear density in units of bits per inch) multiplied by the number of tracks available per unit length in the radial direction of the disc (track density in units of track per inch or TPI). Currently, there is a need for areal densities on the order of 100 Gb/in2 which requires track density on the order of 200-350 kTPI and greater.
One limiting factor to the track density, at which a disc drive is capable of operating, is the track width within which data can be written by the write element. The track width of the write element is generally defined by the width of the top pole. The above-mentioned track density demands generally require top pole widths in the sub-micron (xcexcm) range or on the order of 0.1 to 0.2 xcexcm. Furthermore, the top pole must be formed very accurately (e.g., within +/xe2x88x920.01 xcexcm). These constraints push the resolution capabilities of conventional photolithographic processing techniques thereby making it extremely difficult to pattern such narrow top poles. The resulting top pole widths that can be accurately formed using conventional photolithographic techniques are on the order of 0.6 xcexcm. As a result, new processing techniques are required to accurately form top pole structures having sufficiently small widths that will allow a write element to satisfy the demands for high TPI.
Therefore, a continuing need exists for improved methods of forming a top pole of a write element having a sub-micron track width.
The present invention provides a method of manufacturing a top pole of a write element having a narrow width that allows the write element to record data at a high areal density to satisfy current and future demands for increased data storage. In the method, a first trench is formed on a top surface of a bottom pole. The first trench includes a first opening defined by opposing first side walls and an exposed portion of the top surface located therebetween. Next, a second trench is formed within the first trench. The second trench includes a second opening defined by opposing second side walls formed adjacent the first side walls and a gap member formed on the exposed portion of the top surface of the bottom pole between the second side walls. Finally, the top pole is formed in the second opening which is narrower than the first opening.
In another embodiment, the thickness of the gap member of the second trench is reduced, and a third trench is formed within the modified second trench. The top pole is then formed within a third opening of the third trench that is narrower than the second opening.
Also disclosed is a write element for use in a head of a disc drive storage system that includes a narrow top pole formed in accordance with the above method.
Additional features and benefits of the present invention will become apparent with the careful review of the following drawings and the corresponding detailed description.